Reinforcement bar fastener and tool

ABSTRACT

A reinforcement bar fastener and a tool for securing reinforcement bar members to together to form a metal mesh and a reinforcement bar tool for deforming the reinforcement bar fastener around the reinforcement bar members.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority under 35 U.S.C. §120 and 365(c) to PCT Application No. PCT/2013/020345, filed Jan. 4, 2013, which PCT application claims priority under §119 to U.S. Provisional Application Ser. No. 61/583,686 filed on Jan. 6, 2012. Each of the aforementioned applications is incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fastener for securing metal bars, such as reinforcement bars (rebar members) together. The present invention also relates to a pneumatic, electronic, gas-combustion or hand-operated tool for bending the fastener around the rebar members and in particular to such a device which is portable and can be used on the ground at construction sites.

2. Description of the Related Art

Steel rebar members generally used in the concrete industry are tied together using wire. The wire is either hand tied or automatically tied using rebar tying tools. In most of the tying operations, the wire is fed around two bars, and then the wire is twisted.

SUMMARY OF THE INVENTION

In an embodiment of the present invention, a reinforcement bar fastener (rebar fastener) has a substantially T-shaped body with an upper horizontal portion that fauns a crossbar between and is integral with a lower pair of legs.

In an embodiment of the present invention, there is a fastening tool for applying a driving force to the reinforcement bar fastener to bend the fastener around rebar members to secure the rebar members to each other. The fastening tool can have a body including a driver that provides a downward force on the crossbar portion of the rebar fastener while retractable anvil arms bend the lower vertical leg portions of the rebar fastener upward around the arranged rebar members. The fastening tool includes clamping arms that close the fastener around arranged rebar members to join the rebar members together while applying a force to the crossbar portion of the fastener.

In an embodiment described below, a fastener includes a pair of legs arranged parallelly. The pair of legs including a first leg having opposite first and second ends and a second leg having opposite first and second ends. A crossbar is provided having a center section and a pair of projecting ears extending from the center section. The pair of projecting ears include a first ear having a first end connected to the center section and a second end connected to the first end of the first leg and a second ear having a first end connected to the center section and a second end connected to the first end of the second leg.

In an embodiment, a fastening tool for deforming a rebar fastener around arranged rebar members is provided. The tool includes a portable housing assembly and a nosepiece carried by the portable housing assembly. The nosepiece has a drive track and at least a portion of the drive track is defined by a portion of the nosepiece. A fastener driver is movably mounted in the drive track for deforming a first portion of the rebar fastener. A magazine assembly is constructed and arranged to feed successive leading fasteners from a supply of fasteners contained therein along a feed track and into the drive track. A power operated system is constructed and arranged to be actuated so as to move the fastener driver through successive operative cycles. Each cycle includes a drive stroke wherein a fastener in the drive track is deformed around rebar members to be secured together, and a return stroke. An actuating mechanism includes a trigger assembly having a trigger constructed and arranged to actuate the power operated system in response to the trigger being pulled. A carriage is slidably mounted to the nosepiece. A pair of claws is mounted to the carriage for holding one of a plurality of rebar members in position for fastening. A pair of anvil anus are pivotably connected to the nosepiece. Each anvil arm carries an anvil for deforming a second portion of the rebar fastener.

In an embodiment, there is a method of fastening rebar members together using a deformable rebar fastener. The deformable rebar fastener has a generally T-shaped body formed of a pair of legs arranged in parallel to form an open end and a crossbar having an upper portion and a lower portion forming a closed end. The crossbar is arranged to span and be connected to the pair legs. The pair of legs and the crossbar are in the same lateral plane. The method includes arranging the rebar members to form an upper rebar member and a lower rebar member and positioning the rebar fastener open end over the arranged rebar members so that the legs straddle the rebar members and the crossbar spans the upper rebar member. A first force is applied to the upper portion of the crossbar in the direction of the longitudinal axis of the legs, to bend the crossbar toward the legs. A second force is applied to each of the legs in opposing directions perpendicular to the first force. The legs are bent by the forces in a direction extending 45 degrees from the plane of the crossbar with each leg being bent in opposite directions around the arranged rebar members.

In the embodiments of the present invention, the fastening tool can accommodate rebar members arranged perpendicularly, or parallel or a range of angles. Further, joining rebar members with a pneumatic, electronic, gas-combustion or hand-operated tool of the present invention is less demanding on the body of the user than hand-tying. In addition, providing in a single tool the components to secure together both perpendicularly and parallelly arranged rebar members while accommodating tightly collated fasteners and to produce an increased tightness in the connection between the rebar members, results in cost savings and flexibility in constructing rebar that is not present in existing rebar construction tools.

Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure, its application and/or uses in any way.

BRIEF DESCRIPTION OF THE DRAWINGS

The numerous advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying figures. In the drawings, like reference numerals designate corresponding parts throughout the several views.

FIGS. 1 a-1 c illustrate front, top and side views, respectively, of an exemplary rebar fastener constructed in accordance with the teachings of the present disclosure;

FIG. 2 illustrates a front perspective view of the rebar fastener of FIG. 1 a before bending;

FIG. 3 illustrates the rebar fastener of FIG. 1 a after bending;

FIGS. 4 a-4 c illustrate the bending stages of the crossbar portion of the rebar fastener of FIG. 1;

FIGS. 5 a-5 d illustrate exemplary views of the rebar fastener joining a pair of rebar members arranged parallelly;

FIGS. 6 a-6 d illustrate exemplary views of the rebar fastener joining a pair of rebar members arranged perpendicularly;

FIGS. 7 a-7 d illustrate an embodiment showing forces applied to the rebar fastener to bend the fastener around the rebar members arranged in parallel;

FIGS. 8 a-8 d illustrate an embodiment showing forces applied to the rebar fastener to bend the fastener around the rebar members arranged perpendicularly;

FIG. 9 illustrates the perpendicularly arranged rebar member secured with the rebar fastener of the present invention

FIG. 10 illustrates the parallelly arranged rebar members secured with the rebar fastener of the present invention;

FIG. 11 illustrates a rear perspective view of the rebar fastening tool with the rebar fastener magazine;

FIG. 12 illustrates a rear perspective view of the rebar fastening tool without the rebar fastener magazine;

FIGS. 13 a-13 d illustrate exemplary views of the rebar fastening tool holding rebar members in position for fastening;

FIG. 14 illustrates initial and final shapes of the rebar fastener

FIGS. 15 a-15 b illustrate front views of the anvil arms of the rebar fastening tool in open and closed positions, respectively;

FIGS. 16 a-16 b illustrate top perspective views of the anvil arm rotation;

FIGS. 17 a-17 b illustrate bottom views of the anvil arm rotation;

FIGS. 18 a-18 b illustrate a rebar fastener engaged with rebar members and anvils of the rebar fastening tool;

FIG. 19 illustrates a rebar fastener engaged with the fastener driver and anvils of the rebar fastening tool; and

FIGS. 20 a-20 b 1 illustrate the rebar fastening tool of the present invention arranged within a power source.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings.

FIGS. 1-10 of the drawings illustrate the rebar fastener for joining individual rebar members together to form a grid, such as a steel mesh.

The rebar fastener 10 of the present invention is an elongated member, such as, for example, a wire having a substantially T-shaped body. The T-shaped body is formed from a leg portions 12 arranged in parallel and a crossbar portion 14 that extends between the pair of legs. The pair of legs includes a first leg 12 a having opposite first 12 a-1 and second ends 12 a-2 and a second leg 12 b having opposite first 12 b-1 and second ends 12 b-2. The pair of legs 12 a, 12 b can have the same length, such as length L2, substantially the same length, or have different lengths.

The crossbar portion 14 has a looped or folded form such that a lower portion 14 b of the crossbar is folded beneath or adjacent to an upper portion 14 a of the crossbar. The lower portions 14 b of the crossbar are connected to the upper portions of the legs 12 a-1, 12 b-1 of the rebar fastener 10. The upper portion 14 a of the crossbar includes a center section 14 c that extends in a direction perpendicular to the legs 12. The crossbar portion 14 also includes a pair of projecting ears 14 d, 14 e that extend laterally from the center section 14 c. The pair of projecting ears 14 d, 14 e includes a first ear 14 d and a second ear 14 e. The first ear 14 d can be U-shaped and have one end connected to the center section 14 c and the other end connected to one of the legs, such as the first leg 12 a, for example, at 12 a-1. The second ear 14 e can also be U-shaped and have one end connected to the center section 14 c and the other end connected to the second leg 12 b, such, for example, at 12 b-1.

The crossbar 14 of the rebar fastener 10 can be integral with the pair of legs 12. For example, the rebar fastener 10 can be formed from a single strand of material, and bent into the shape of the T-shaped body described above. Alternatively, the rebar fastener can be formed from a plurality of strands of the same material. Additionally, a plurality of materials can be used to form the rebar fastener. The intersection of the crossbar and the legs, such as at 12 a-1 and 12 b-1, can be curved surfaces. Also, the projecting ears can have a curved or arcuate surface such that there are no sharp edges that could break upon deformation of the rebar fastener.

As shown in FIGS. 1 b and 1 c, the crossbar 14 and the legs 12 are located in the same plane. Also, as shown in FIG. 1 a, the in-plane bounds of the crossbar 14 extend beyond the legs 12, forming the projecting ears 14 d, 14 e on each side of the legs. The length of the crossbar extension beyond the legs can be the same for both the first ear section and the second ear section. Alternatively, one of the projecting ears can extend farther beyond the legs than the other ear section.

In the undeformed state of the rebar fastener 10, as shown in FIGS. 1 a and 2, the projecting ears 14 d, 14 e of the crossbar 14 are angled away from the pair of legs 12. For example, the first ear 14 d and second ear 14 e can be angled away from the pair of legs 12 at an angle Φ of more than 90 degrees. In one example, the first ear and second ear can be angled away from the pair of legs at about 105 degrees. The first ear and second ear can also be configured to have different angles.

The center section 14 c of the crossbar 14, located between the projecting ears 14 d, 14 e, can be configured to be perpendicular to the pair of legs 12. In this configuration, the center section 14 c is horizontal with respect to the projecting ears 14 d, 14 e which are angled away from the legs 12. The first ear 14 d and second ear 14 e can be angled away from the center section 14 c at an angle θ greater than zero degrees, for example, at an angle of about 15 degrees.

The rebar fastener 10 is designed to hold rebar members together. In this regard, the legs 12 of the rebar fastener 10 can be deformed around the body of the rebar members and conform to the shape of the rebar members. The crossbar 14 can be flattened across an uppermost surface of the rebar members. FIG. 2 is a perspective view of the rebar fastener prior to deformation. FIG. 3 illustrates an exemplary rebar fastener that has been deformed around rebar members.

FIGS. 4 a-4 c illustrate the bending stages of the crossbar 14 in the deformation of the rebar fastener 10 shown in FIG. 1 a. A force F1 is applied to the projecting ears 14 d, 14 e, which are located at the distal end portions of the crossbar 14, along the longitudinal direction of the legs 12, to bend the crossbar toward the legs. The force F1 applied to the projecting ears of the crossbar can bend the crossbar towards the legs and permanently deform the crossbar. As a result, the crossbar acts as a spring as it relaxes in a direction opposite to the rebar held by the rebar fastener, in order to compensate for relaxation or “springback” that occurs in the legs after the fastener has been deformed into position, such as, for example, around the rebar members. For example, the projecting ears 14 d, 14 e of the crossbar can initially form an angle of 105 degrees with the legs and 15 degrees with the center section 14 c. Although the projecting ears 14 d, 14 e are initially angled away from the legs 12, when deformed around the rebar members, the upper section 14 a of the crossbar 14 is bent to be substantially flat as shown in FIG. 4 c or further bent to form an acute angle with respect to the legs. In this shape, the projecting ears 14 d, 14 e are permanently deformed in the same longitudinal plane as the center section 14 c. Hence the springback resulting from this permanent deformation, of the crossbar acting in a direction opposite to that resulting from the deformation of the legs, results in a loading of the uppermost portion of the crossbar of the fastener as a leaf spring. Although the example above provides that the projecting ears can form an angle of, for example, 15 degrees with the center section and 105 degrees with the legs, any combination of angles between the center section of the crossbar and the projecting ears and the projecting ears with the legs can be formed.

The legs of the rebar fastener provide the principal connection for fastening rebar members together. In an undeformed state, the legs 12 of the rebar fastener are initially in the same lateral plane as the crossbar. As seen in FIG. 3, for example, upon deformation, the legs are bent in a direction extending 45 degrees from the plane of the crossbar with each leg being bent in opposite directions.

The rebar fastener is designed to be deformed around sections of rebar to secure the rebar members to each other. The rebar fastener 10 can be deformed by applying forces to different portions of the fastener to bend the fastener around the rebar members. The forces can be applied to the crossbar 14 and the legs 12 with a tool. In an embodiment, the tool can be manual, electrically powered, driven by gas combustion, or pneumatically and apply forces as show in FIGS. 7 a-7 d and 8 a-8 d.

To secure the rebar members together with the rebar fastener 10, the rebar fastener is positioned over the upper rebar member so that the crossbar 14 spans an upper rebar member 20 and the legs 12 straddle both upper 20 and lower 22 rebar members as shown for example in FIGS. 5 a-5 d and 6 a-6 d. The rebar members can be arranged with an upper rebar 20 member in parallel with a lower rebar member 22 as shown in FIGS. 5 a-5 d and 7 a-7 d or an upper rebar member 20 crossing a lower rebar member 22 perpendicularly, as shown in FIGS. 6 a-6 d and 8 a-8 d.

The rebar fastener 10 can be deformed by applying a force F1 on the projecting ears 14 d, 14 e of the crossbar 14 in the longitudinal direction of the legs 12 as shown in FIGS. 7 a and 8 a. The force can be applied by a tool or device designed for bending rebar fasteners and can include a fastener driver (not shown) that applies the force F1. The fastener driver presses the projecting ears downward (along a negative Y-axis) until the projecting ears are substantially flattened along the X-axis as shown in FIGS. 7 b and 8 b. The projecting ears bend as a result of the applied force F1. FIG. 4 b, for example, illustrates vertical forces applied against the projecting ears 14 d, 14 e causing one ear to move in a clockwise direction and the other ear to move in a counterclockwise direction. The fastener driver can apply a variable or constant force to the rebar fastener.

The legs 12 of the rebar fastener 10 can be positioned against a portion of the tool body and deformed by forces applied in laterally opposing directions to the legs.

The tool or device can include articulated arms 24 including a roller portion 26 that rolls the legs 12 upward around the lower rebar member about the Z-axis as shown in FIGS. 7 b and 8 b. The roller portion 26 applies a force F2 to the legs 12 of the rebar fastener. The force F1 applied by the fastener driver to the projecting ears 14 d, 14 e can also be applied at the same time as the articulated arms 24 and roller portion 26 apply the force F2 to roll the legs or in a sequential order.

The tool or device that applies forces to the rebar fastener, as shown in FIGS. 7 c 1 and 8 c 1, can then be removed from the rebar fastener 10 allowing the projecting ears 14 d, 14 e and legs 12 to relax. FIGS. 7 c 2 and 8 c 2 show the crossbar 14 as flat across the upper rebar 20, in a position that compensates for the springback in the legs 12. In order to offset the relaxation of the legs 12 upon release of the tool after deformation of the rebar fastener 10, the crossbar 14 is bent by application of a force displacing the projecting ears 14 d, 14 e. As such, when the tool is released and the crossbar 14 and the legs 12 relax, generally simultaneously, the crossbar will absorb the relaxation of the legs and continue to provide tension in the fastener by being displaced further in the longitudinal direction than the bent legs. The final connection of the rebar fastener to the rebar members 20, 22 is shown in FIGS. 7 d and 8 d.

FIG. 9 illustrates perpendicularly arranged rebar members 20, 22 secured with the rebar fastener 10 of the present invention. FIG. 10 illustrates parallelly arranged rebar members 20, 22 secured with the rebar fastener of the present invention.

The body of the rebar fastener 10 can be metallic and formed from a strand of steel wire, for example. Alternatively, the body of the rebar fastener can be die-cut or formed from a strip of steel or formed from steel sheets through a progressive stamping operation. Other materials that can be used to form the fastener include plastic or a composite material. Further, a combination of materials or material properties can be used for the fastener.

In order to create a secure rebar joint, springback in the legs must be reduced. If springback in the legs is not reduced, then after being deformed around the rebar members, when the legs relax and loosen, the joint can become weakened. The geometry of the rebar fastener of the present embodiments is such that the length L1 of the crossbar 14 can be greater than the length L3 between the first 12 a and second 12 b legs, as shown in FIG. 1 a, for example. Also, for example, the ratio of the length L3 between the legs 12 a and 12 b to the length L1 between the projecting ears 14 d, 14 e can be within a range of 30-40%.

The geometry ensures that, upon deformation of the rebar fastener 10, the springback in the crossbar 14 is greater than the springback in the legs 12, which creates a secure joint for holding the rebar members together. In order to create a more secure or tighter joint for holding the rebar members, the crossbar 14 can be heat-treated while the legs remain un-treated. Heat treating the crossbar 14 results in increased compensation for springback in the legs 12. Heat-treating substantially increases the crossbar yield strength over the crossbar yield strength without heat-treating. The higher yield strength produces a greater displacement of the projecting ears 14 d, 14 e away from the center section 14 c and results in the increased compensation for springback in the legs.

The rebar fastener can also be deformed with a reinforcement bar fastening tool (rebar fastening tool). FIGS. 11-20 illustrate an embodiment of the rebar fastening tool of the present invention. The rebar fastening tool drives the rebar fastener toward the rebar members and bends the rebar fastener to fasten two rebar members together. As shown in FIGS. 11 and 12, the tool 30 includes a housing 31, nosepiece 32, fastener driver 34, a trigger assembly having a trigger 33, anvils 36 mounted on anvil arms 38, a carriage 40 and claws 42 attached to the carriage. The nosepiece 32 has a longitudinal axis and is connected to the housing 31. The nosepiece acts as a guide for the fastener driver 34 and includes a drive track 56. At least a portion of the drive track 56 is defined by a portion of the nosepiece 32. The fastener driver 34 is arranged between the nosepiece 32 and magazine assembly 44 and is connected to the piston (not shown). The carriage supports the claws and positions to rebar relative to the fastening tool. The carriage 40 circumscribes the nosepiece 32 and slides in a direction parallel to a longitudinal axis of the nosepiece.

As shown in FIG. 11, the magazine assembly 44 stores a plurality of rebar fasteners 10 in an array. A pusher 50 in the magazine assembly feeds the fasteners along a feed track 58 to the driving track of the fastener driver 34 of the tool 30. When a predetermined number of fasteners remain in the magazine assembly, a dry-fire lockout can be engaged to prevent the tool from actuating. The plurality of fasteners can be collated with a glue or tape, for example.

A power operated system 60 is constructed and arranged to be actuated so as to move the fastener driver 34 through successive operative cycles. Each cycle includes a drive stroke wherein the rebar fastener 10 in the drive track 56 is deformed around rebar members 20, 22 to be secured together, and a return stroke. The trigger assembly is part of an actuating mechanism and includes the trigger 33. The trigger assembly is constructed and arranged to actuate the power operated system in response to the trigger 33 being pulled.

The claws 42 of the tool have a shape that corresponds to the shape of the rebar member. For example, as shown in FIG. 11, the claws 42 can have an arcuate body having a concave surface that corresponds to the convex outer surface of the lower rebar member 22. The claw 42 can be configured to engage the upper surface of the lower rebar member 22 to hold the rebar member in place while the rebar fastener is being deformed therearound. A U-shaped channel 46 on the bottom of the magazine assembly holds the upper rebar member 20. FIGS. 13 a-13 d illustrate different views of the tool 30 and the anvil arms 38 holding the lower rebar member 20 in position for fastening to the upper rebar member 22. FIG. 14 illustrates the initial and final shapes of the rebar fastener 10.

The anvil anus 38 are spring-biased outward, away from the nosepiece 32, so as to fit over the space around the rebar members. A spring (not shown) can be located between the anvil arms and the nosepiece 32, for example. Alternatively, the spring can be arranged in a position that biases the anvil arms 38 away from the nosepiece 32. The anvil arms 38 have an inner portion that faces the nosepiece and an outer portion that faces away from the nosepiece. The anvil arms 38 are pivotable on pivot point 54. The pivot point 54 for the anvil arms 38 is mounted to the nosepiece 32. The claws 42 of the rebar tool 30 grasp the lower rebar member 22 to hold the rebar member in position for fastening. During the fastening process, the anvil arms 38 of the tool, which carry the anvils 36, rotate toward each other to a position underneath the rebar members as shown in FIGS. 15 a, 15 b, 16 a and 16 b. Rollers 48 in the carriage 40 travel with the carriage vertically along the nosepiece. The rollers 48 engage cam surfaces 52 that can be integral with the outer portion of anvil arms 38 to move the anvil arms inward. Alternatively, the cam portions 52 can be separate members, having cam surfaces, which are mounted to the anvil arms 38. The rollers 48 limit the outward movement of the anvil arms 38 to a predetermined position. The anvil arms 38 continue to rotate until the cam portions 52 located on the outer portion of the anvil arms engage the rollers 48 as shown in FIG. 15 a. At this point, the anvils 36 mounted on the anvil anus 38 are positioned under the rebar members 20, 22. During the deformation of the rebar fastener 10, an additional clamping force to that provided by the rollers on the cam portion 52 can be applied to the anvil arms 38. The additional clamping force can be provided by a variety of means, including, but not limited to, pneumatic cylinders that press against the sides of the anvil arms 38.

When the carriage 40 is located at the bottom stroke of a rotation, the tool operator can actuate the tool 30 to move the fastener driver 34 to separate one rebar fastener 10 from a plurality of rebar fasteners stored in the magazine assembly 44 on the tool. The fastener driver 34 forces the rebar fastener 10 into a radiused path inside the anvil arms 38 and underneath the lower rebar member 22, as shown in FIGS. 17 a and 17 b. FIG. 18 a illustrates the rebar fastener 10 positioned over the upper rebar member 20 so that the crossbar 14 spans the upper rebar member and the legs 12 straddle both the upper 20 and lower 22 rebar members. FIGS. 18 b and 19 illustrate the fastener driver 34 pressing the projecting ears 14 d, 14 e downward along the negative Y-axis until the projecting ears are flattened along the X-axis as shown in FIG. 16. The anvil arms 38 roll the legs 12 around the lower rebar member 22 about the Z-axis. The rebar fastening tool 30 is then removed from the rebar fastener allowing the crossbar 14 and legs 12 to relax on the joined rebar members, thereby completing the process of the rebar fastener securing the rebar members to each other.

In operation, the tool operator can arrange the rebar members in an upper rebar member and a lower rebar member configuration. The rebar members can be arranged parallelly, perpendicularly, or in a range of angles therebetween. The tool operator can position the tool 30 above the rebar members to be fastened. The pusher 50 in the magazine 44 moves successive fasteners to the drive track 56 that is slidably mounted to the nosepiece 32. The open end of the leading rebar fastener 10 can be placed over the arranged pair of rebar members 20, 22 so that the legs 12 straddle the rebar members and the crossbar 14 spans the upper rebar member 20. The nosepiece, which is fixed, can be placed onto the crossbar portion 14 of the rebar fastener 10.

A first force from the fastener driver can be applied to the upper portion of the crossbar in the direction of the longitudinal axis of the legs, to bend the projecting ears 14 d, 14 e toward the legs 12. A second force can be applied to each of the first 12 a and second 12 b legs in opposing directions perpendicular to the first force. The first force and second force can be applied serially or simultaneously. The application of the first force and second force can bend the legs in a direction extending 45 degrees from the plane of the crossbar 14 with each leg 12 a, 12 b being bent in opposite directions around the rebar members 20, 22.

FIGS. 20 a-20 b illustrate a rebar fastening tool arranged within a pneumatic power source such as an engine. The pneumatic power source includes an enclosure 62 for housing a high pressure tank 64, a handle 66, a trigger extension 68, a shut-off valve 70, a tank support 72, and a regulator 74 to control the high pressure fluid. The trigger 33 can be controlled by the trigger extension 68.

While the rebar fastening tool is illustrated as being pneumatically powered by a suitable power source, such as compressed air, those skilled in the art will appreciate that the invention, in its broader aspects, may be constructed somewhat differently and that aspects of the present invention may have applicability to electrically powered driving tools, powered by a battery pack. In addition, to a pneumatic and electronic powered tool, the tool can also be powered by gas-combustion, or hand-operated with a mechanical advantage.

Furthermore, while aspects of the present invention are described herein and illustrated in the accompanying drawings in the context of a rebar fastening tool, those of ordinary skill in the art will appreciate that the invention, in its broadest aspects, has further applicability. For example, the fastening tool of the present invention includes features such as a clawing motion that may also be applicable for tying land erosion netting, in agricultural applications and in pipe-fitting. Further, the rebar fasteners of the present invention may have applicability for fastening pipes or conduits as typically found in the pipe-fitting and electrical trades.

It will be appreciated that the above description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. While specific examples have been described in the specification and illustrated in the drawings, it will be understood by those of ordinary skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure as defined in the claims. Furthermore, the mixing and matching of features, elements and/or functions between various examples is expressly contemplated herein, even if not specifically shown or described, so that one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise, above. Moreover, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular examples illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out the teachings of the present disclosure, but that the scope of the present disclosure will include any embodiments falling within the foregoing description and the appended claims. 

We claim:
 1. A fastener comprising: a pair of legs arranged parallelly, the pair of legs including a first leg having opposite first and second ends and a second leg having opposite first and second ends; a crossbar having a center section and a pair of projecting ears extending from the center section, the pair of projecting ears including a first ear having a first end connected to the center section and a second end connected to the first end of the first leg and a second ear having a first end connected to the center section and a second end connected to the first end of the second leg.
 2. The fastener of claim 1, wherein the pair of legs and the crossbar are formed in the same plane.
 3. The fastener of claim 1, wherein the first ear and second ear are angled away from the pair of legs.
 4. The fastener of claim 3, wherein the first ear and second ear are angled away from the pair of legs at an angle of about 105 degrees.
 5. The fastener of claim 1, wherein the center section is configured to be perpendicular to the pair of legs.
 6. The fastener of claim 5, wherein the first ear and second ear are angled away from the center section at an angle of about 15 degrees.
 7. The fastener of claim 1, wherein the fastener is formed of a metal wire.
 8. The fastener of claim 1, wherein the fastener is formed of a material comprising at least one of steel, plastic, and a composite.
 9. The fastener of claim 1, wherein the pair of legs and crossbar are integrally formed of a single wire strand.
 10. The fastener of claim 1, wherein the fastener is substantially T-shaped.
 11. The fastener of claim 1, wherein the length of the crossbar is greater than the length of each of the legs.
 12. A fastening tool comprising: a portable housing assembly; a nosepiece carried by the portable housing assembly, the nosepiece having a drive track, at least a portion of the drive track being defined by a portion of the nosepiece; a fastener driver movably mounted in the drive track; a magazine assembly constructed and arranged to feed successive leading fasteners from a supply of fasteners contained therein along a feed track and into the drive track; a power operated system constructed and arranged to be actuated so as to move the fastener driver through successive operative cycles, each cycle including a drive stroke wherein a fastener in the drive track is deformed around rebar members to be secured together, and a return stroke; an actuating mechanism including a trigger assembly having a trigger constructed and arranged to actuate the power operated system in response to the trigger being pulled; a carriage slidably mounted to the nosepiece; a pair of claws mounted to the carriage for holding one of a plurality of rebar members in position for fastening; and a pair of anvil arms pivotably connected to the nosepiece, each anvil arm carrying an anvil.
 13. The fastening tool according to claim 12, wherein the nosepiece is fixed in the tool.
 14. The fastening tool according to claim 12, wherein the carriage circumscribes the nosepiece slides along the longitudinal axis of the nosepiece.
 15. The fastening tool according to claim 12, wherein the fastener driver slides along the nosepiece.
 16. The fastening tool according to claim 12, further comprising a U-shaped channel on a bottom surface of the magazine assembly for holding at least one rebar member to be fastened.
 17. The fastening tool according to claim 12, wherein the anvils include a plurality of grooves for guiding portions of a fastener to deform around the rebar members to be secured together.
 18. The fastening tool according to claim 12, wherein the carriage comprises rollers for stopping pivotal movement of the anvil arms.
 19. The fastening tool according to claim 18, wherein the anvil arms have cam surfaces disposed on an outer portion thereof configured to engage the rollers on the carriage.
 20. A method of fastening rebar members together using a deformable rebar fastener, the deformable rebar fastener having a generally T-shaped body formed of a pair of legs arranged in parallel to form an open end and a crossbar having an upper portion and a lower portion forming a closed end, the crossbar being arranged to span and be connected to the pair legs, the pair of legs and the crossbar being in the same lateral plane, the crossbar, the method comprising: arranging the rebar members to form an upper rebar member and a lower rebar member; positioning the rebar fastener open end over the arranged rebar members so that the legs straddle the rebar members and the crossbar spans the upper rebar member; applying a first force to the upper portion of the crossbar in the direction of the longitudinal axis of the legs, to bend the crossbar toward the legs; applying a second force to each of the legs, the second force being applied in opposing directions perpendicular to the first force, wherein the legs are bent in a direction extending 45 degrees from the plane of the crossbar with each leg being bent in opposite directions around the arranged rebar members. 